With the Occupy Wall Street protests gaining steam in the U.S., it seems obvious to link the movement with the other grassroots movement that recently shook up American politics: the Tea Party. President Barack Obama did it this morning, telling ABC that the protesters in downtown New York are “not that different” from the Tea Party: both the right and the left feel “that their institutions aren’t looking out for them.”

My colleagues’ pieces number among a flurry of others pondering the parallel. Michael Scherer recast Occupy Wall Street as the Tea Party of the American left. Roya Wolverson suggested how the two movements, coming from diametrically opposed sides of the political spectrum, could find common ground (and perhaps policy influence) in their mutual distaste for a Washington dominated by the vested interests of corporations. But while the similarities are noteworthy, they obscure more relevant truths about Occupy Wall Street, the supposedly inchoate movement that has transfixed the American media in recent weeks. I enumerate these truths after the jump.

1. Occupy Wall Street is an expression of a global phenomenon. A cursory glimpse at newspapers over the weekend would have shown scenes of mass protest across European capitals and cities elsewhere in the world, all in solidarity with the antigreed protesters in New York City. The Tea Party, for all its early brio, commands no such solidarity, nor does it care for it. It’s a hyper-nationalist movement in the U.S., lofting the totems of the Constitution and the flag. Few viable political factions across the Atlantic advocate the Tea Party’s anti–Big Bovernment, libertarian agenda (though the xenophobic, culturally conservative wing of the Tea Party would perhaps see eye to eye with Europe’s Islamophobic far right).

Many of the Occupy Wall Street participants, on the other hand, consciously see themselves as part of a worldwide uprising, a flame kindled by the Arab Spring and borne across the Mediterranean by anti-austerity protesters in Europe. In all three settings, social media has played a vital role in mobilizing and organizing the disaffected and the disenfranchised. In all three settings, activists and protesters have drawn from, in varying degrees, a toolbox of leftist, anarchist protest tactics and made do with minimal institutional support or funds. And in all three settings, the protesters have pulled together sympathizers from myriad political camps within their countries and somehow made a virtue out of having a lack of central leadership. The U.S. economy may not be facing the same existential pressures as those of Greece or Spain, nor are American protesters facing the sort of desperate brutality meted out on brave dissidents in Tunisia, Egypt or Syria. But the call for social justice echoes the same across continents.

2. Occupy Wall Street is fueled by youth. Reporters covering the ongoing occupation of Zuccotti Park have encountered and profiled a host of characters from all walks and stages of life. One of my favorite interviews so far has been Marsha Spencer, a 56-year-old grandmother who can be found on weekends at the park’s western edge, knitting gloves and scarves for fellow protesters. She makes no bones about what’s driving Occupy Wall Street: young people, including college students saddled with years of debt, 20-somethings struggling to land a job and an entire generation banging its head on what seems to be the ever lowering ceiling of their possibilities. “It’s all about them,” Spencer told me on a rainy morning last week in Zuccotti Park.

Not true for the Tea Party, whose typical supporter is older, wealthier and whiter than the American demographic average. It is a movement, by and large, of the haves — not the have-nots. “It’s essentially reactionary,” says David Graeber, a professor of anthropology at Goldsmiths College, University of London, who helped set up Occupy Wall Street’s much-heralded general assembly and is one of the first people to push the movement’s now ubiquitous slogan “We are the 99%.” “The Tea Party core group is white middle-class Republicans who are angry that they seem to be losing their position of preeminence in society,” he says. The ranks of Occupy Wall Street, on the other hand, are most heavily populated by young people, who, says Graeber, “are supposed to be the ones at the forefront, reimagining their society.” Their protest fits into a long continuum of student and youth rebellions, most recently seen in the Mediterranean rim countries mentioned above.

3. Occupy Wall Street may prove much harder to co-opt into the political mainstream. Many have speculated on what direction Occupy Wall Street will turn as it picks up momentum and encroaches on the U.S.’s 2012 presidential race. Will the movement be co-opted by the country’s big unions? Will Washington-based advocacy groups like MoveOn.org try to exploit for its own ends the success of motley, diverse bands of protesters occupying dozens of downtowns across the U.S.? And most important, will Occupy Wall Street radicalize the Democratic base the way the Tea Party energized the far right of the Republicans?

At present, it’s hard to see how Occupy Wall Street could generate the left-wing, Democratic versions of Rand Paul or Michele Bachmann. Few of the protesters one speaks to have any tolerance for either political party, which they say are equally enmeshed in a political system entirely beholden to vested corporate interests. The Tea Party, boosted by financial titans and an influential cable news network, was able to make the leap from grassroots anger to effective Beltway politicking. Occupy Wall Street has no such benefactors nor mouthpiece, and will have to undergo a massive — and potentially divisive — transformation should it become the sort of tempered, streamlined (what many would deem compromised) political player that can throw its weight behind the Obama Administration. For the time being, it remains a social movement far more interested in the sort of direct democracy practiced during occupations than that which gets negotiated in the corridors of power in Washington. The sentiments below may have been expressed by an exasperated Greek blogger in June, but they reverberate around Zuccotti Park today:

We will not suffer any more so that we can make the rich, even richer. We do not authorise any of the politicians, who failed so spectacularly, to borrow any more money in our name. We do not trust you or the people that are lending it. We want a completely new set of accountable people at the helm, untainted by the fiascos of the past. You have run out of ideas.

4. Occupy Wall Street still believes in politics and government. And this is where another important line has to be drawn. Whereas much of the Tea Party’s programmatic ire seems directed at the very idea of government — and instead trumpets the virtue of self-reliance and the inexorable righteousness of the free market — Occupy Wall Street more sharply decries the collusion of corporate and political elites in Washington. The answer, for many of the protesters I’ve spoken to, is never the wholesale dismantling or whittling away of the capabilities of political institutions (except, perhaps, the Fed), but a subtler disentangling of Wall Street from Washington. Government writ large is not the problem, just the current sort of government.

Because at the end of the day, Occupy Wall Street, like most idealistic social movements, wants real political change. Excited activists in Zuccotti Park spoke to me about the advent of “participatory budgeting” in a number of city council districts in New York — an egalitarian system, first brought about in leftist-run cities in Latin America, that allows communities to dole out funds in their neighborhoods through deliberation and consensus building. It’s the same process that gets played out every day by the activist general assemblies held in Zuccotti Park and other occupation sites around the U.S. To the outside observer, that may seem foolishly utopian — and impracticable on a larger scale — but it’s a sign of the deep political commitment of many of the protesters gathering under Occupy Wall Street’s banner. They want to fix government, not escape from it.